There is growing concern that waste streams from hospitals, slaughter houses, and other sources that may contain biologically hazardous and other toxic or objectionable components are not adequately treated before discharging such waste streams to sanitary sewer systems or directly to the environment. Large municipal treatment facilities may not adequately be configured for high concentrations of biological and chemical materials originating in hospitals and other sources. Accordingly, there is a need for improved systems and methods for treating waste streams before the streams are discharged into a sanitary sewer system or directly to the environment. There is also a need for modular systems that may be readily deployed before an inlet to an existing sanitary sewer system at the source of the waste stream thereby reducing the infectivity and toxicity of material that a municipal system must treat.
In view of the foregoing and other needs, an exemplary embodiment of the disclosure provides a modular waste treatment system for liquid waste streams and methods of treating liquid waste streams are disclosed. The modular waste treatment system includes a maceration chamber for initial treatment and homogenization of waste material; a metal ion infusion chamber in fluid flow communication with the maceration chamber for introducing metal ions into the waste material; and an oxidation chamber for wet oxidation of the waste stream. Provision may be made to recycle the waste to one or more of the chambers for further treatment if required.
Another exemplary embodiment of the disclosure provides a method of treating a liquid waste material to provide a treated waste stream. The method may include flowing a waste stream into a modular waste treatment system. The modular waste treatment system may include a maceration chamber for initial treatment and homogenization of waste material; a metal ion infusion chamber in fluid flow communication with the maceration chamber for introducing metal ions into the waste material; and an oxidation chamber for oxidizing oxidizable material in the waste stream. The waste stream is macerated to a predetermined particle size and may be contacted with a film inhibitor in the maceration chamber. Metal ions are generated in the metal ion infusion chamber for contact with the waste stream from the maceration chamber to partially detoxify and to promote the oxidation process of the waste stream. The waste stream is then oxidized in the presence of oxygen to provide a treated stream that is substantially devoid of toxic and active biological materials.
An advantage of the system and methods described herein is that the system combines at least two disinfection techniques in a single unit thereby increasing the effectiveness of waste stream treatment over the use of a single disinfection technique. The oxidation system used is essentially flameless and therefore does not introduce any combustion products into the atmosphere. However, heating both the waste stream and the oxygen stream may greatly promote the reaction rate. The use of elemental oxygen also provides a much more compact system than units using air (containing only about 20 wt. % oxygen).
Because of the modular components of the system, the system may be configured as a mobile, or portable, stand-alone unit or may be provided in a substantially fixed non-portable installation that may be inserted between a waste material source and a final disposition of the waste material. The waste treatment system may also be combined and/or integral with a waste collection system. In another embodiment, the waste treatment system may be a stand alone system for discharge of treated wastes to the environment.
Additional objects and advantages of the disclosure will be set forth in part in the description which follows, and/or can be learned by practice of the disclosure. The objects and advantages of the disclosure may be realized and attained by means of the elements and combinations particularly pointed out in the appended claims.
It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the disclosure, as claimed.